Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G18/00—Polymeric products of isocyanates or isothiocyanates
  • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
  • C08G18/28—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen characterised by the compounds used containing active hydrogen
  • C08G18/40—High-molecular-weight compounds
  • C08G18/48—Polyethers
  • C08G18/4866—Polyethers having a low unsaturation value
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G18/00—Polymeric products of isocyanates or isothiocyanates
  • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
  • C08G18/08—Processes
  • C08G18/10—Prepolymer processes involving reaction of isocyanates or isothiocyanates with compounds having active hydrogen in a first reaction step

Definitions

• the present invention relates to NCO prepolymers having a low monomer content and prepared from isophorone diisocyanate (IPDI) and polypropylene oxide glycols, to a process for the production thereof and to their use.
• IPDI isophorone diisocyanate
• polypropylene oxide glycols to a process for the production thereof and to their use.
• NCO prepolymers A multitude of NCO prepolymers and binders obtained therefrom are known (for example EP-A 0 497 131 or EP-A 1 138 707).
• Prior art NCO prepolymers are produced by reacting relatively high molecular weight polyhydroxyl compounds, such as polyether or polyester polyols, with excess quantities of di- or polyisocyanate. It is advantageous in this connection if the isocyanate groups exhibit different reactivities. This property of “selectivity” suppresses any unwanted monomer content. These products also exhibit low viscosities and better industrial processability.
• Isophorone diisocyanate (3-isocyanatomethyl-3,3,5-trimethylcyclohexyl isocyanate, IPDI) has two such differently (selectively) reactive isocyanate groups.
• DD-A 151466 Another option is described in DD-A 151466, in which prepolymers having a low monomer content are produced by reacting di- or polyisocyanates with polyalcohols using hydroxy-functional organometallic catalysts.
• these prepolymers can only be produced with the use of solvents, some of which remain in the prepolymer. This is disadvantageous for reasons of occupational hygiene, especially when these prepolymers are subsequently used in paints for producing coatings in poorly ventilated areas.
• a low residual monomer content of diisocyanate according to DD-A 151466 is only achieved by using elevated contents of hydroxy-functional organometallic catalysts.
• An object of the present invention is to provide solvent-free, NCO prepolymers prepared from IPDI and polyhydroxyl compounds and having a residual IPDI monomer content of ⁇ 2.0 wt. %, which prepolymers should be directly usable without a distillation process for removing the monomers and do not exhibit the stated disadvantages.
• this object may be achieved by using polypropylene oxide glycols, which have been produced using the DMC catalyst process (for example, U.S. Pat. No. 3,278,459, WO 97/29 146 or EP-A 0 573 206). Without any elaborate distillation step, the monomer content is less than 2.0 wt. % and thus lower than when conventional polypropylene oxide glycols produced using the KOH process are used.
• the present invention relates to solvent-free, NCO prepolymers having a residual IPDI monomer content of less than 2.0 wt. %, an NCO content of 2.0 to 5.0 wt. % and a viscosity of 5000 to 20,000 mPa ⁇ s, wherein the NCO prepolymers are the reaction products of
• the present invention also relates to a process for preparing these solvent-free, NCO prepolymers by reacting
• the present invention relates to polyurethane coating, sealant, adhesive and/or embedding compositions containing the solvent-free, NCO prepolymers as a binder and/or binder component.
• the NCO prepolymers according to the invention have a residual IPDI monomer content of less than 2.0 wt. %, preferably less than 1.95 wt. %; an NCO content of 2.0 to 5.0 wt. %, preferably of 3.0 to 4.5 wt. %, and more preferably of 3.5 to 4.2 wt. %; and a viscosity of 5000 to 20,000 mPa ⁇ s, preferably 8000 to 15,000 mPa ⁇ s and more preferably 9000 to 13,000 mPa ⁇ s at 23° C.
• the NCO prepolymers are obtained by reacting 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate and one or more polyethers prepared by the DMC catalyst process and having an OH-functionality of 1.80 to 2.00, preferably 1.90 to 2.00 and more preferably of 1.98 to 2.00, at an NCO/OH ratio of 1.5:1 to 2.2:1, preferably 1.7:1 to 2.0:1 and more preferably of 1.80:1 to 1.98:1 in the presence of at least one catalyst at 20 to 100° C.
• the solvent-free, NCO prepolymers according to the invention are produced by initially introducing IPDI together with a catalyst and then adding at least one polyether at a temperature of between 20° C. and 100° C.
• the polypropylene oxide glycols are distinguished in that they have been produced from propylene oxide using a double metal cyanide catalyst (DMC catalyst) instead of the conventional potassium hydroxide, and consequently exhibit a greater OH-functionality and lower monool content than those which have been produced in conventional manner using potassium hydroxide as catalyst (c.f. for example U.S. Pat. No. 3,278,459, U.S. Pat. No. 3,404,109, U.S. Pat. No. 3,829,505, WO 97/29 146 or U.S. Pat. No. 3,941,849).
• DMC catalyst double metal cyanide catalyst
• the polyethers preferably used to produce the solvent-free, NCO prepolymers NCO according to the invention are those having an average OH-functionality of between 1.98 and 2.00 and a number average molecular weight of 500 to 5000 g/mol, preferably 1000 to 2000 g/mol.
• polyether polyols are produced by polymerizing propylene oxide in the presence of a DMC catalyst, such as zinc hexacyano-cobaltate, at 130° C., for example, using the process described in WO 97/29,146 (Examples 1 to 5) with incremental addition of starter.
• Continuous starters which are suitable include water or low molecular weight polyols having a molecular weight of less than 300 g/mol, such as glycerol, propylene glycol, dipropylene glycol, ethylene glycol, trimethylolpropane and sorbitol.
• Catalysts which may be used for the reaction of IPDI and the polyethers include organometallic compounds of the elements aluminium, tin, zinc, titanium, manganese, iron, bismuth and zirconium. Examples include dibutyltin laurate, zinc octoate and titanium tetraisopropylate. Tertiary amines, such as 1,4-diazabicyclo[2.2.2]octane, are also suitable.
• polyethers used in the following examples were produced in a polymerization process by reacting propylene oxide with the assistance of a DMC catalyst at 130° C. in accordance with the process described in WO 97/29,146, Examples 3-5, with continuous apportionment of starter.
• Arcol® PPG 2000 is a polypropylene oxide glycol having a number average molecular weight (Mn) of 2000 g/mol can be produced as follows:
• Arcol® PPG 1000 was also obtained as a polypropylene oxide glycol with a number average molecular weight (Mn) of 1000 g/mol.
• the prepolymer according to the invention had a viscosity of 10800 mPa ⁇ s (23° C., plate viscosimeter), an NCO content of 3.9 wt. % and a monomer content of IPDI of 1.80 wt. % (determined by gas chromatography).
• the prepolymer according to the invention had a viscosity of 11300 mPa ⁇ s (23° C., plate viscosimeter), an NCO content of 3.9 wt. % and a monomer content of IPDI of 1.90 wt. % (determined by gas chromatography).
• the prepolymer had a viscosity of 9200 mPa ⁇ s (23° C., plate viscosimeter), an NCO content of 3.9 wt. % and a monomer content of IPDI of 2.15 wt. % (determined by gas chromatography).
• the prepolymer had a viscosity of 9200 mPa ⁇ s (23° C., plate viscosimeter), an NCO content of 3.9 wt. % and a monomer content of IPDI of 2.07 wt. % (determined by gas chromatography).

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• Chemical & Material Sciences (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Polyurethanes Or Polyureas (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
• Paints Or Removers (AREA)
• Adhesives Or Adhesive Processes (AREA)
• Sealing Material Composition (AREA)

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Citations (9)

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• 2001
  • 2001-12-14 DE DE10161386A patent/DE10161386A1/de not_active Withdrawn
• 2002
  • 2002-12-02 AU AU2002358075A patent/AU2002358075A1/en not_active Abandoned
  • 2002-12-02 ES ES02791754T patent/ES2360086T3/es not_active Expired - Lifetime
  • 2002-12-02 EP EP02791754A patent/EP1458780B1/de not_active Expired - Lifetime
  • 2002-12-02 CA CA2470007A patent/CA2470007C/en not_active Expired - Fee Related
  • 2002-12-02 CN CNB028248988A patent/CN100537627C/zh not_active Expired - Lifetime
  • 2002-12-02 AT AT02791754T patent/ATE499393T1/de active
  • 2002-12-02 DE DE50214927T patent/DE50214927D1/de not_active Expired - Lifetime
  • 2002-12-02 WO PCT/EP2002/013589 patent/WO2003051950A1/de active Application Filing
  • 2002-12-02 JP JP2003552826A patent/JP2005511872A/ja active Pending
  • 2002-12-02 PT PT02791754T patent/PT1458780E/pt unknown
  • 2002-12-11 US US10/316,364 patent/US6825376B2/en not_active Expired - Lifetime
• 2005
  • 2005-09-29 HK HK05108654.5A patent/HK1076635A1/xx not_active IP Right Cessation

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